Is the Seasonal Variation of Abundance and Species Richness in Birds Explained by Energy Availability?
Is the Seasonal Variation of Abundance and Species Richness in Birds Explained by Energy Availability?
复制标题
鸟类数量和物种丰富度的季节性变化可以用能源可用性来解释吗？
DOI：
10.3161/00016454ao2017.52.2.005
复制
发表时间：
2017
影响因子：
0.7
通讯作者：
Brandl Roland
中科院分区：
文献类型：
--
作者：
R. Pfeifer;J. Stadler;Brandl Roland
抽象的。
能源供应解释了物种丰富度的空间变化。然而，在北极到温带地区，鸟类的物种丰富度也表现出季节性模式，夏季物种数量高，冬季数量低。有没有可能用夏季高可用性和冬季低可用性来解释这种模式？“能量可用性假说”依赖于丰度和物种丰富度之间的正相关关系。使用每周计数沿着样带在北方巴伐利亚州（南德国），我们发现了预期的季节性年度以及两年周期的物种丰富度（共观察到108种）。与此相反，个体数量没有明显的季节性周期，但不稳定的波动，特别是在冬季。气候条件对个体数量和物种丰富度的影响很小。在分析中加入天气变量只增加了1.5%到10%的解释方差。能量有效性假说不能解释温带地区物种丰富度的季节变化。然而，冬季的鸟类群落由能够以各种资源类型为食的物种组成，特别是夏季产生的种子。这些剩余的食物为饮食通才提供了过冬的资源。
Abstract.
Energy availability explains the spatial variation of species richness. However, in arctic to temperate regions species richness in birds shows also a seasonal pattern with high species numbers in summer and low numbers in winter. Is it possible to explain this pattern by high energy availability in summer and low availability in winter? The ‘energy availability hypothesis’ rests on a positive correlation between abundance and species richness. Using weekly counts along a transect in Northern Bavaria (S Germany), we found the expected seasonal annual as well as biannual cycles in species richness (108 species observed in total). In contrast, the number of individuals showed no clear seasonal cycle, but erratic fluctuations particularly in winter. Weather conditions had only small effects on the number of individuals and on species richness. Adding weather variables to analyses increased explained variance only by 1.5% to 10%. The energy availability hypothesis is not able to explain the seasonal variation of species richness in temperate regions. However, bird assemblages during winter consist of species able to feed on various resource types, in particular seeds produced during summer. These left-overs provide the resources for diet generalists to survive the winter.